The digital age has provided great convenience to society with regard to the online availability of entertainment content. What once began as a trip to the theatre to see a movie became a trip to the video store to pick up a digital video disc (DVD) and now is a selection on the television screen to stream a content provider's movie from a service provider to the subscriber's client device for playback.
A realized requirement of the evolution of digital content and the ability to transmit the digital content from a service provider to a subscriber's client device is the need for encrypting the digital content before transmission to protect the property rights of the content provider. Historically, a content provider delivered unprotected digital content to a service provider. The service provider, using a DRM system based on the cable headend/client device combination selected by the service provider, encrypted the digital content. The encrypted content was then delivered to authorized service provider subscribers, along with a key required for decryption. The client device, manufactured with a specific DRM system vendor's decryption module, combined the key with the decryption module, decrypted the content and presented the content to the user.
As the DRM system market evolved, an increasing number of DRM system vendors appeared, providing incompatible proprietary DRM systems. Over time, a service provider distributed client devices from different manufacturers, with different DRM system decryption modules. Consequently, when a subscriber selected digital content, the service provider had to determine which client device was in use and deliver the encrypted digital content compatible with the decryption module in use by the client device.
The net result of the distribution of client devices with different DRM system implementations is the requirement for a service provider to maintain multiple copies of the same content, with each copy implementing a different DRM system. The redundancy of encrypted digital content is required because the state of the art for client devices is hard coded support for a single DRM system and its associated decryption module.
In another shortcoming of the state of the art in service provider based content delivery systems, the content provider is unable to select a DRM system vendor of their choice and deliver the service provider encrypted content and a decryption system useable by the service provider's installed client devices. Demand is increasing for content providers to select their own DRM system and deliver encrypted content. Further, service providers would like the flexibility to select new content delivery systems based on advances in technology and a competitive marketplace instead of a selection based predominantly on the cost of replacing the installed base of client devices.
Market pressure for a solution allowing a client device to decrypt a content provider's content regardless of the DRM system vendor selected by the content provider has led to several attempts to solve the problem. For instance, a DRM system vendor can provide different decryption algorithms associated with their proprietary DRM system but not allow decryption of content encrypted by other DRM system vendors. Although these attempts are useful, they still require the service provider to maintain one copy of the encrypted content for each supported DRM system vendor. They do not, however, allow a client device to decrypt a content provider's content regardless of the DRM system implemented by the content provider or the service provider.
Accordingly, it would be desirable to provide a solution that allows a service provider to maintain a single copy of a content provider's content, encrypted by a DRM system of the content/service provider's choosing, and a client device capable of decrypting content encrypted by any available DRM system. The solution should also provide, among other things, the ability for a content/service provider to change DRM systems without requiring the distribution of new client devices by the service provider. Further, the solution should allow a service provider to select a new hardware vendor for their cable headend/client devices without requiring the content/service provider to change DRM system vendors.